Much of the literature on the epistemology of disagreement focuses on the rational responses to disagreement, and to disagreement with an epistemic peer in particular. The Equal Weight View claims that in cases of peer disagreement each dissenting peer opinion is to be given equal weight and, in a case of two opposing equally-weighted opinions, each party should adopt the attitude which ‘splits the difference’. The Equal Weight View has been taken by both its critics and its proponents to have (...) quite drastic skeptical ramifications given contingent empirical facts that we are aware of regarding disagreements in philosophy, religion, science, and politics. In this paper,we begin by clarifying the central claims of the Equal Weight View (Section 2) and then examine two routes from the Equal Weight View to skepticism about such matters that have been explored in the literature. The first claims that our awareness of peers or experts who disagree with us about such issues requires that we abandon our beliefs on these issues (Section 3). The second claims that our awareness of merely possible peers or experts who disagree with us requires us to abandon our beliefs (Section 4). We find both routes from the Equal Weight View to a form of skepticism defective. However, there are nearby considerations, explored in Sections 5 and 6,which (for better or worse) do lead to at least some skeptical consequences for the Equal WeightView, albeit for different reasons. (shrink)

The Uniqueness Thesis, or rational uniqueness, claims that a body of evidence severely constrains one’s doxastic options. In particular, it claims that for any body of evidence E and proposition P, E justifies at most one doxastic attitude toward P. In this paper I defend this formulation of the uniqueness thesis and examine the case for its truth. I begin by clarifying my formulation of the Uniqueness Thesis and examining its close relationship to evidentialism. I proceed to give some motivation (...) for this strong epistemic claim and to defend it from several recent objections in the literature. In particular I look at objections to the Uniqueness Thesis coming from considerations of rational disagreement (can’t reasonable people disagree?), the breadth of doxastic attitudes(can’t what is justified by the evidence encompass more than one doxastic attitude?), borderline cases and caution (can’t it be rational to be cautious and suspend judgment even when the evidence slightly supports belief?), vagueness (doesn’t the vagueness of justification spell trouble for the Uniqueness Thesis?), and degrees of belief (doesn’t a finegrained doxastic picture present additional problems for the Uniqueness Thesis?). (shrink)

Knowledge and its Limits presents a systematic new conception of knowledge as a kind of mental stage sensitive to the knower's environment. It makes a major contribution to the debate between externalist and internalist philosophies of mind, and breaks radically with the epistemological tradition of analyzing knowledge in terms of true belief. The theory casts new light on such philosophical problems as scepticism, evidence, probability and assertion, realism and anti-realism, and the limits of what can be known. The arguments are (...) illustrated by rigorous models based on epistemic logic and probability theory. The result is a new way of doing epistemology and a notable contribution to the philosophy of mind. (shrink)

The knowledge account of assertion holds that it is improper to assert that p unless the speaker knows that p. This paper argues against the knowledge account of assertion; there is no general norm that the speaker must know what she asserts. I argue that there are cases in which it can be entirely proper to assert something that you do not know. In addition, it is possible to explain the cases that motivate the knowledge account by postulating a general (...) norm that assertions would be true, combined with conversational norms that govern all speech acts. A theory on which proper assertions must be true explains the data better than a theory on which proper assertions must be known to be true. (shrink)

A rational person doesn’t believe just anything. There are limits on what it is rational to believe. How wide are these limits? That’s the main question that interests me here. But a secondary question immediately arises: What factors impose these limits? A first stab is to say that one’s evidence determines what it is epistemically permissible for one to believe. Many will claim that there are further, non-evidentiary factors relevant to the epistemic rationality of belief. I will be ignoring the (...) details of alternative answers in order to focus on the question of what kind of rational constraints one’s evidence puts on belief. Our main question concerns how far epistemic permission and obligation can come apart.1 Suppose I am epistemically permitted to believe P, i.e., it would not be irrational for me to believe it. Am I thereby obliged to believe P, or are other options rationally available to me?2 Might I be equally rational in remaining agnostic about P, or even believing not-P? Or could even a slightly stronger or weaker degree of confidence be just as reasonable? (shrink)

How should one react when one has a belief, but knows that other people—who have roughly the same evidence as one has, and seem roughly as likely to react to it correctly—disagree? This paper argues that the disagreement of other competent inquirers often requires one to be much less confident in one’s opinions than one would otherwise be.

Looking back on it, it seems almost incredible that so many equally educated, equally sincere compatriots and contemporaries, all drawing from the same limited stock of evidence, should have reached so many totally different conclusions---and always with complete certainty.